Here are some instruction of how to install in to a 90's Bally Williams WPC series Pinball

Note: There will be slight variations from person to person, but please feel free to share any tips / tricks.

Bally / WMS WPC

1. Remove the glass
2. Lift the playfield so the brackets rest at the lockdown bar location
3. Check the playfield for any parts which may scratch the mirror blades
4. Do a test fit - so slide the correct blade into each side to test fit / clearance and then remove
5. Tilt the playfield into the vertical position against the back box so you can get the maximum access for mounting
6. Loosen the back box hinge screw - removing only the internal bolt - leave the external bolt still in place.
7. Remove the protective plastic around the hinge hole only at this stage
7. Mount the mirror blade over the bolt


Double sided tape method
8. Re-mount the back box hinge bolt but keep slightly loose so the blade can be carefully be positioned
9. Do a test alignment - mainly watch the top edge is lined up with the timber edge just under the glass rubber channel but make sure it sits 0.5 - 1mm under so the glass can not dig into the blade - use some regular tape along the top edge to keep it in position.
10. Tighten up the Backbox hinge screw.
11. Do a test lowering of the play field to check for catches - if it does catch do not force it - return to the vertical position and check what caused the snag. In edition if anything catches it will be the playfield on the very back screw or bottom blade edge due to the angle of the playfield going through it's movements in the machine to standing vertical.
12. Once all ok, return the playfield to the vertical position and then swivel the blade out so you can remove the backing off the double sided tape. Swivel the blade back down and secure the tabs of double sided tape.
13. Once all fastened remove the protective film.
14. Optional - Place adhesive felt to the edge of the play field from the front to as far as visible while the play field is in the vertical position.
15. Carefully lower the playfield and reassemble the glass and lockdown bar.
16. You are ready to enjoy.

3 Small Screw method
8. Re-mount the back box hinge bolt but keep slightly loose so the blade can be carefully be positioned
9. Tighten up the Backbox hinge screw - mainly watch the top edge is lined up with the timber edge just under the glass rubber channel but make sure it sits 0.5 - 1mm under so the glass can not dig into the blade, use some regular tape along the top edge to keep it in position.
10. Select the correct screw that is no longer than 1/2 the thickness of the cabinet and screw in carefully and ensure that it is a countersunk style screw where the screw can sit fairly flush - due to blade thickness you will never get a screw head flush. Many people only use 1 screw at the front and one at the back
11. Do a test lowering of the playfield to check for catches - if it does catch do not force it so return to the vertical position and check what caused the snag. In edition if anything catches it will be the play field on the very back screw or bottom blade edge due to the angle of the playfield going through it's movements of in the machine to standing vertical.
12. Return the playfield to the vertical position and then remove the protective film.
13. Optional - Place adhesive felt to the edge of the play field from the front to as far as visible while the play field is in the vertical position.
14. Carefully lower the play field and reassemble the glass and lockdown bar.
15. You are ready to enjoy.


Perform the same steps for the both sides for the option that you have chosen

Important Safety Note for the Williams based only on a few reports on Pinside of grounding issues (but neither supplier of blades have issued this issue - I can not confirm that this a wise thing to do or not - this is purely a awareness note: Open the backboard and remove the three bolts that secure the hinge. Cut the ground strap away from the hinge and re-secure. This prevents the mirror blade from becoming a huge ground plane. Possibly an option is on powering the machine check to see if the blade has any current - though I will need a person with better electronics knowledge to detail the best way to test for this.